Expi293™ Expression System
High-Density Mammalian Transient Protein Expression
- Higher transfection efficiency
- Up to 10x greater protein yield
- Improved cell viability
- Smaller culture volumes
Quote From Researcher
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The Expi293™ Expression System is a major advancement in transient expression technology for rapid and ultra high-yield protein production in mammalian cells. It is based on high density culture of Expi293F™ cells in Expi293™ Expression Medium. Transient expression is powered by the new cationic lipid-based ExpiFectamine™ 293 transfection reagent in combination with optimized transfection enhancers designed to work specifically with this transfection reagent. All components work in concert to generate 2- to 10-fold higher protein yields than conventional culture systems such as the FreeStyle™ 293 Expression System. Expression levels of greater than 1 g/L were achieved for IgG and non-IgG proteins (See Figure 1).
Learn about Expi293™ system on the ambr™ platform for automated protein expression
 | Figure 1. Expression of human IgG and Fc-tagged Cripto achieve expression levels of over 1g/L in the Expi293™ Expression System. |
What’s in the System?
The components included in the kit are:
- 2 vials of frozen Expi293F™ cells
- 1 liter of Expi293™ Expression Medium
- 1 ExpiFectamine™ 293 Transfection Kit, sufficient to transfect 1 liter of culture
- OptiMEM® Reduced Serum Medium
- An Antibody-Expressing Positive control
The ExpiFectamine™ 293 Reagent and ExpiFectamine™ 293 Transfection Enhancers 1 and 2 are sold together as the ExpiFectamine™ 293 Transfection kit. All other components of the system are available separately.
What Makes Expi293™ Expression System Unique?
Expi293™ Expression Medium is a chemically defined, serum-free, protein-free medium. Expi293™ Expression Medium enables high density cell culture (See Figure 2) and transfection, allowing for significantly higher volumetric protein yields than traditional culture systems.
 | Figure 2. Cell viability and viable cell density over time for cells grown in Expi293™ Expression Medium vs. other 293 culture media. |
Expi293F™ cells are specifically adapted to exhibit higher pg/cell/day productivity than typical 293 cells and produce up to 1.7x more protein than Freestyle™ 293F cell when used in the Expi293™ Expression System.
ExpiFectamine™ 293 transfection reagent is capable of high-efficiency transfection of high-density 293 cultures, and is coupled with transfection enhancers that further boost transfection performance and expression levels. (See Figure 3).
 | Figure 3. Expression of hIgG, with and without transfection enhancers. |
How Does the Kit Work?
The Expi293™ Expression System contains all the components needed to easily produce high levels of recombinant protein in your own laboratory. The only additional component required is a mammalian expression vector containing the DNA for your protein of interest.
Expi293F™ cells are thawed and grown in suspension culture in Expi293™ Expression Medium. Cells are typically grown in flasks on a shaker platform inside a CO2 cell culture incubator or in bioreactors. The cells are transfected using ExpiFectamine™ 293 Transfection Reagent. Transfection enhancers 1 and 2 are then added to the culture 16-18 hours post-transfection. There is no need to change culture medium or otherwise supplement the cultures during protein production. Protein harvest can be performed from 2 to 7 days post-transfection, depending on the expression profiles of the protein of interest. For expression of recombinant antibodies, maximum yields are often seen from 5 to 7 days post-transfection.
The system is highly scalable and should produce similar volumetric protein yields in transfection formats ranging from 1 mL cultures in a 24-well plate up to 1L cultures in shake flasks (See Figure 4).
 | Figure 4. Expression of Fc-tagged Cripto achieves similar volumetric protein yields at 3 different scales. |
The Expi293™ Expression System is a rapid method of producing mg to gram quantities of recombinant protein in mammalian cells. For the expression of human or other mammalian proteins, expression in the human-derived 293 cells offers the benefit of more native folding and post-translational modifications, such as glycosylation, when compared to expression systems based on hosts such as E. Coli, yeast, or insect cells.
Expi293™ System Cost Comparison Chart
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*Protein yields in each culture are expressed as normalized values, based on the amount obtained using FreeStyle™ Expression Medium supplemented with PEI in 1 L of culture.
†Disposable Erlenmeyer shake flasks, Cost/unit:
500 mL, non-baffled, vent cap - $18.00
1000 mL, non-baffled, vent cap - $25.81
3000 mL, Fernbach-style, non-baffled, vent cap - $58.51
